The conventional methods of prolonging a life of a cut flower and maintaining its freshness include a method of cutting the flower in fresh water; a method of crushing or burning the cut surface to improve preservation in water; a method of adding a nutrient source such as sugars to water; and a method of adding a preservative or germicide for preventing multiplication of a microorganism or fungus, an aggregating and precipitating agent for colloidal particles, such as aluminum sulfate, for the purpose of aggregating colloidal particles such as a substance leaked from the plant or a metabolite occurring upon generation of microorganisms, or chemicals such as silver thiosulfate for suppressing biosynthesis of ethylene; etc. That is, various techniques have been devised. Then, various agents for prolonging the life of the cut flower are commercially available.
However, the publicly known methods described above suffer from the various problems that their effect on keeping the freshness of the cut flower and vegetable is not satisfactory, that the limited type of the cut flower and vegetable is demonstrated to be effected, their procedure to use themselves is complicated, and the safety on the environment and humans and domestic animals is worried about.
Further, JP-A 6-336401 discloses a technique wherein a perfume glycoside enhances an aroma of a cut flower.
On the other hand, JP-A 6-227904 and JP-A 7-330502 only disclose techniques of keeping a freshness of a cut flower or the like by use of trehalose or a salt thereof but don't disclose a surfactant etc.